Golf club grip

ABSTRACT

The present invention is directed to a method of displaying indicia on a golf club shaft having a substantially translucent grip. The indicia are permanently formed on an outer surface of the shaft by chemical etching, bead blasting, stamping, and the like. The grip is held on top of the gripping end of a shaft by a translucent glue or liquid adhesive. The grip is made from a rubber base or synthetic material. This method of displaying indicia is innovative because the indicia are protected from abrasion.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 11/758,998, filed Jun. 6, 2007, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to grips and shafts for sports implements, and more preferably to indicia that are etched on the shafts of golf clubs, and viewed through translucent or transparent grips.

BACKGROUND OF THE INVENTION

Grips of golf clubs are typically formed from strips of synthetic resin or rubber. Such grips are wrapped spirally around golf club shafts. To commemorate sports meetings or special events from time to time, stickers with graphics or characters are attached on the external surface of golf club grips. However, sweat tends to loosen the stickers, and the adhesive from the stickers soils golfers' hands.

Accordingly, there is a need in the art for a means for displaying desired information or decorative designs on sports equipment such as golf clubs. The means for displaying information should protect the displayed information or designs from damage and from wear and tear, while not interfering with the primary function of providing a secure gripping area for the golfer.

SUMMARY OF THE INVENTION

A method of displaying indicia on the gripping end of a golf club shaft, wherein the indicia is formed into an outer surface of the shaft, by chemical etching, engraving, bead blasting, or stamping. The use of a translucent or transparent grip allows the indicia to be viewed. The grip may be attached to the shaft by a translucent or transparent glue or liquid adhesive, so as not to interfere with the display of the indicia. The grips may be made from a rubber or synthetic material.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

FIG. 1 is a perspective view of golf club grip according to the invention, shown mounted on a golf club shaft;

FIG. 2 is an axial sectional view of the golf club grip; and

FIG. 3 is a flow chart depicting a method for displaying indicia on a golf club shaft.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a method of displaying indicia on a golf club shaft having a substantially translucent or transparent grip. The indicia are permanently formed on an outer surface of the shaft by chemical etching, engraving, bead blasting, stamping, and the like. The grip is held on top of the gripping end of a shaft by a translucent or transparent glue or liquid adhesive. The grip is made from a rubber base or synthetic material.

The grip can be transparent, translucent or semi-transparent. As used herein, the term “transparent,” in reference to an object, means that the object has an average transmittance of visible light (e.g., between about 380 nm and about 770 nm or alternately between about 400 nm and about 700 nm) of at least about 40%, preferably at least about 50%, more preferably at least about 60%. The average transmittance referred to herein is typically measured for incident light normal (i.e., at approximately 90°) to the plane of the object and can be measured using any known light transmission apparatus and method, e.g., a UV-Vis spectrophotometer.

As used herein, the terms “translucent” and “semi-transparent,” in reference to an object, mean that the object has an average transmittance of visible light (e.g., between about 380 nm and about 770 nm or alternately between about 400 nm and about 700 nm) of at least about 10%, preferably at least about 20%, more preferably at least about 30%.

Hence, as used herein, the term “translucent” or “semi-transparent” encompasses translucent, semi-transparent, and transparent.

As shown in FIGS. 1 and 2, golf club grip 10 is shaped and dimensioned to fit about the gripping end of a golf club shaft 12. The gripping end of golf club shaft 12 is typically the proximal end of golf shaft 12. As with most golf club grips, the present golf club grip 10 has a cavity 14, which is tapered as it extends from proximal end 16 to distal end 18. This allows the grip 10 to conform to the shape of conventional club shafts 12. A butt 20 may also be molded with a hole 22 in its center. Grip 10 is substantially translucent, which allows indicia 24 to be formed underneath it and visible through grip 10. As used herein, the term “indicia” includes letters, numbers, logos, signatures, symbols, shapes, patterns, and the like.

FIG. 3 illustrates an innovative method 100, according to the present invention, whereby one can display indicia 24 on a golf club shaft 12. In step 110, a golf club shaft 12 is selected. In step 120, indicia 24 is permanently produced by etching the outer surface of the gripping end of golf shaft 12, which is typically made of stainless steel. In step 120, a plurality of methods can be used to etch the stainless steel and thereby permanently create indicia 24, including, without limitation, chemical etching, mechanical etching (e.g., via a drill or engraving tool), bead blasting, stamping, and the like.

Chemical etching is one technique that can be used to form indicia 24. More particularly, chemical etching involves the removal of material from substrates such as stainless steel to form the indicia. Generally, chemical etching can be wet or dry. Wet etchants are typically acids or alkalis. Hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, acetic acid, phosphoric acid, hydrogen peroxide, and mixtures thereof are non-limiting examples of wet acidic etchants. Sodium ammonia, potassium hydroxide, tetramethyl ammonium hydroxide, ammonium hydroxide, sodium hydroxide, cerium hydroxide, and mixtures thereof are non-limiting examples of wet alkali etchants. Wet chemical etching can be accomplished using commercially available kits such as ETCH-O-MATIC® (available from Martronics Corp. of Salkum, Wash.). The ETCH-O-MATIC® kit includes stencils, which can be used in conjunction with wet acidic or alkali etchants to produce desired patterns or designs such as indicia 24. The ETCH-O-MATIC® wet etchants can also promote colors such as red and blue.

Dry etching typically involves bombarding a substrate such as stainless steel with plasma. Plasmas are highly ionized gases composed of ions, electrons, and neutral particles. Plasma etchants typically include nitrogen, chlorine, boron trichloride, and ferric chloride. The bombardment of stainless steel with such plasma etchants results in the formation of a desired pattern or design such as indicia 24. Further discussion of chemical etchants, including wet etchants and plasma etchants, can be found in U.S. Pat. No. 6,828,055.

Mechanical etching is another technique that can be used to create indicia 24. More particularly, mechanical etching involves using any suitable tool such as a burin, drill, or other engraving tool to form a pattern or design, such as indicia 24, into the outer surface of a substrate, such as the gripping end of stainless steel shaft 12. Advantageously, one can use mechanical etching to engrave a signature or other custom indicia 24.

Bead blasting is yet another technique that can be used to create indicia 24. More particularly, bead blasting is a process wherein solid particles such as glass beads are forced across a substrate, such as stainless steel, using compressed air. The beads are applied on to the substrate with sufficient momentum so as to abrade the substrate surface. If stencils are placed on top of the substrate surface, the beads will abrade the substrate surface only at certain locations, thereby forming a desired pattern or design such as indicia 24.

Stamping is yet another technique that can be used to create indicia 24 into the outer surface of the shaft. Various forms of stamping are known to persons of ordinary skill in the metal working art. A number of commercial vendors such Lyons Tool and Die Company of Meriden, Conn. specialize in stamping stainless steel as thin as 0.001 inch. By way of example, and without limitation, one type of stamping that can be useful in creating indicia 24 is embossing, which involves using a pair of dies to apply heat and pressure to a substrate such as stainless steel. The combination of heat and pressure produces a desired pattern or design such as indicia 24.

Referring back to FIG. 3, in step 130, grip 10 is held on top of shaft 12 by any suitable adhesive including, but not limited to, glues and liquid adhesives (e.g., hair spray). Grip 10 can be made of a translucent, elastomeric material that is sized to cover the outer surface of shaft 12. The adhesive that holds grip 10 in frictional contact with shaft 12 is also translucent, thereby allowing indicia 24 to remain visible through grip 10.

Grip 10 can be fabricated from natural rubber, synthetic rubber, other synthetic materials, and the like. In one exemplary embodiment, discussed more fully in the parent application, grip 10 can be fabricated from a silicone rubber comprising a polyorganosiloxane polymer, preferably polydimethylsiloxane (“PDMS”). Advantageously, such a silicone rubber composition results in a translucent grip 10 with a soft feel. For instance, the silicone rubber compositions can result in a grip 10 with a Shore A Durometer of about 20-70, preferably about 40-60, more preferably about 53. Moreover, the silicone rubber composition results in grip 10 having a specific gravity of 1.00 or higher, preferably about 1.15. Optionally, color pigments can be added to the silicone rubber composition in order to produce a visually stimulating grip 10 having any suitable color (e.g., the color of jelly), as discussed in the parent application. The silicone rubber composition can further comprise fillers such as fumed silica, processing aids, cure accelerators, cross-link densifiers, texturizing or tackifying materials, and curing agents. Further discussion of suitable silicone rubber compositions can be found in U.S. Pat. No. 5,686,158, which is incorporated herein by reference in its entirety.

A translucent grip 10 is used in combination with a translucent adhesive. This combination is advantageous because it allows indicia 24 to remain visible and observed by the user through grip 10. When light passes through a particular medium, its speed is typically reduced and can cause a distortion of the image observed through the medium. The reduction of speed can be quantified by the index of refraction, which is a value expressed by the ratio n=c/v, wherein c is speed of light in a vacuum and v is the speed of light in a given medium. Thus, a relatively low index of refraction n correlates with a relatively high speed of light v in a given medium. In one particular embodiment of the present invention, the indices of refraction of grip 10 and the adhesive are about 2.0 or less, preferably about 1.5 or less, more preferably about 1.25 or less. Such relatively low indices of refraction help reduce the image distortion of indicia 24 because the speed of light is reduced to a lesser extent.

In yet another embodiment of the present invention, grip 10 can magnify indicia 24 to enlarge its physical appearance. More particularly, grip 10 has a magnification factor from about 2× to about 5× to make indicia 24 appear larger than its actual size. The actual size of indicia 24 is typically small given the limited amount of space in the gripping end of shaft 12. Because the user may not be able to clearly discern relatively small-sized indicia 24, it is advantageous to magnify the physical appearance of indicia 24. Alternatively, grip 24 may also include a separate inner tube made from a magnifying material, such as polycarbonate or glass, or materials that are similar to the lens of reading glasses.

While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objectives of the present invention, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Additionally, feature(s) and/or element(s) from any embodiment may be used singly or in combination with feature(s) and/or element(s) from other embodiment(s). Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments, which would come within the spirit and scope of the present invention. 

1. A method of displaying indicia on a gripping end of a golf club shaft comprising the steps of: (a) forming indicia into an outer surface of the gripping end of the shaft; (b) covering the gripping end with a grip, wherein the grip has an average transmittance of visible light of at least about 10% and an index of refraction of 2.0 or less; and (c) applying an adhesive to the grip, wherein the adhesive has an average transmittance of visible light of at least about 10% and an index of refraction of 2.0 or less.
 2. The method of claim 1, wherein the indicia are written in step (a) by chemical etching, mechanical etching, bead blasting, or stamping.
 3. The method of claim 1, wherein the grip has a magnification factor of at least about 2 to about
 5. 4. The method of claim 1, wherein the grip is made from a rubber base or a synthetic material.
 5. The method of claim 1, wherein the grip has an average transmittance of visible light of at least about 40%.
 6. The method of claim 1, wherein the grip has an index of refraction of 1.25 or less.
 7. The method of claim 1, wherein the adhesive has an average transmittance of visible light of at least about 40%.
 8. The method of claim 1, wherein the adhesive has an index of refraction of 1.25 or less.
 9. A golf club comprising: (a) a shaft having a gripping end with an outer surface having indicia formed thereon; and (b) a grip attached by an adhesive to the outer surface of the shaft, wherein the grip has an average transmittance of visible light of at least about 10% and an index of refraction of 2.0 or less; and wherein the adhesive has an average transmittance of visible light of at least about 10% and an index of refraction of 2.0 or less.
 10. The golf club of claim 9, wherein the indicia are etched by chemical etching, mechanical etching, bead blasting, or stamping.
 11. The golf club of claim 9, wherein the grip has a magnification factor of at least about 2 to about
 5. 12. The golf club of claim 9, wherein the grip is made from a rubber base or a synthetic material.
 13. The golf club of claim 9, wherein the grip has an average transmittance of visible light of at least about 40%.
 14. The golf club of claim 9, wherein the grip has an index of refraction of 1.25 or less.
 15. The golf club of claim 9, wherein the adhesive has an average transmittance of visible light of at least about 40%.
 16. The golf club of claim 9, wherein the adhesive has an index of refraction of 1.25 or less.
 17. The golf club of claim 11 further comprising a magnifying inner tube. 